Communications - Scientific Letters of the University of Zilina, 2006 (vol. 8), issue 1
Articles
Thin-Film Silicon in Photovoltaics: The Role of Structure and Microstructure
Jarmila Mullerova, Pavol Sutta, Stanislav Jurecka
Communications - Scientific Letters of the University of Zilina 2006, 8(1):5-9 | DOI: 10.26552/com.C.2006.1.5-9 
Structure and microstructure of hydrogenated silicon thin films and the influence of the hydrogen dilution of silane plasma at the PEVCD deposition on the film properties were investigated. The results show that at dilution between 20 and 30 the transition between amorphous and crystalline phase occurs. The sample becomes a mixture of amorphous silicon, polycrystalline silicon with nano-sized grains and voids with decreasing hydrogen concentration at grain boundaries and post-deposition oxygen contamination. The dominance of Si-H bonds and presence of interstitial oxygen and oxygen bonded in surface Si-OH groups was observed.
Electrical Characterization of Thin Layer Materials: Destructive and Non-Destructive Irreversible Processes in Langmuir Films
Drahoslav Barancok, Julius Cirak, Pavol Tomcik, Jan Vajda, Martin Weis
Communications - Scientific Letters of the University of Zilina 2006, 8(1):10-12 | DOI: 10.26552/com.C.2006.1.10-12
Summary Well-defined Langmuir-Blodgett films prepared by reproducible technique are still highly attractive for exploitation in investigation of subjects as diverse as chain packing, phase transitions, two-dimensional physics, biosensors and membrane physics. During last 15 years the Maxwell displacement current (MDC) measuring technique was developed for dynamic study of monolayers. In experiment MDC flows through the metal electrode/air gap/Langmuir monolayer/water surface structure. Spontaneous formation of the monolayer was observed and significant differences between destructive and non-destructive processes are discussed.
Scanning of Optical Fields Using Near-Field Scanning Optical Microscopy
Dusan Pudis, Ivan Martincek, Ivan Turek, M. Michalka, J. Kovac, jr., V. Gottschalch, Daniel Kacik
Communications - Scientific Letters of the University of Zilina 2006, 8(1):13-18 | DOI: 10.26552/com.C.2006.1.13-18
The Near-field scanning optical microscopy is a high-resolution diagnostics for the optical field characterization. In our experiments we focus on the optical field characterization of semiconductor laser diodes based on multiple quantum well structure as well photonic crystal fibers. The parameters of optical field of laser diode in the near- and far-field zone as well the local spectral analysis of the quantum well laser devices in the near-field will be studied. The mode distribution across photonic crystal fiber was scanned using near-field scanning optical microscopy. This experimental technique in combination with an analysis of optical field...
Methods of Determination of the Sign of the Thermo-Diffusion Coefficient in Dispersed Liquids
Ctibor Musil, Julius Stelina
Communications - Scientific Letters of the University of Zilina 2006, 8(1):19-21 | DOI: 10.26552/com.C.2006.1.19-21
In this paper three methods of determination of the sign of the thermo-diffusion coefficient (Soret constant) are presented. The first method uses the relation for Soret constant which was derived from the thermo-diffusion equation. This relation permits determination of the sign of the Soret constant as well as its approximate value. The second method is based on the time dependence of the decay of the created diffraction grating. The last method is based on the measurement of the transmission of light by the dispersion liquid.
Thin Film Optical Parameters Determination by the Dynamical Modelling and Stochastic Optimization Method
Stanislav Jurecka, Jarmila Mullerova
Communications - Scientific Letters of the University of Zilina 2006, 8(1):22-24 | DOI: 10.26552/com.C.2006.1.22-24
We report on a new method of experimental data processing to obtain optical parameters of thin films. Dynamical modelling of the spectral reflectance can be performed interactively in a graphical environment by the genetic search in wide interval of parameter space and then refined by the genetic algorithm method, by the Nelder-Mead downhill simplex method or Marquardt-Levenberg method. Optical parameters of hydrogenated amorphous silicon (a-Si:H) thin film used in solar cell technology are determined by this new method. The spectral reflectance is a function of optical properties and the thickness of the film. Optical parameters found by our approach...
Radiation Hardness of Mos Structures Exposed to High-Energy Ions
Ladislav Harmatha, L. Stuchlikova, P. Pisecny
Communications - Scientific Letters of the University of Zilina 2006, 8(1):25-28 | DOI: 10.26552/com.C.2006.1.25-28
MOS structures exposed to 305 MeV Kr and 710 MeV Bi ions irradiation with fluences of 109 cm2 and 1010 cm2 were investigated by capacitance measuring methods (C-V, C-t), completed by quasistatic low-frequency C-V and DLTS measurements.The irradiated MOS structures were functional in spite of a high density of radiation defects. The electric activity of the defects brought a sharp decrease in the generation parameters tr and g. The parameters of six deep levels were detected in the MOS structures exposed to 710 MeV Bi ions irradiation. Five of these levels with energies 0.52 eV, 0.14 eV, 0.17 eV, 0.25 eV, 0.27 eV were radiation defects.
Eddy Current Non-Destructive Evaluation of Conductive Materials
Ladislav Janousek, Tomas Marek, Daniela Gombarska
Communications - Scientific Letters of the University of Zilina 2006, 8(1):29-33 | DOI: 10.26552/com.C.2006.1.29-33
Non-destructive methods of material properties evaluation are presented in the paper. The methods are useful especially for increasing the safety of sophisticated and environment threatening facilities and, consequently, for decreasing the operating expenditures of those facilities. The attention is paid mainly to the method that utilises eddy currents induced in the surface layer of conducting samples by means of a small flat coil. The eddy current testing method is theoretically described and results of its particular application are presented in the paper.
Improvement of Power Electronic Structure Characteristics Using Sic Technology - Overview
Branislav Dobrucky, Pavol Spanik, Robert Sul
Communications - Scientific Letters of the University of Zilina 2006, 8(1):34-38 | DOI: 10.26552/com.C.2006.1.34-38
This paper is dedicated to the recent unprecedented boom of SiC electronic technology. The contribution deals with a brief survey of those properties. In particular, the differences (both good and bad) between SiC electronics technology and well-known silicon VLSI technology are highlighted. Projected performance benefits of SiC electronics are given for several large-scale applications at the end of the contribution. The basic properties of SiC material were discussed already at the beginning of 1980's, also in our work place [1].
Diamond and DLC Layers for a Wide Range of Aplications
Marian Vojs, M. Vesely
Communications - Scientific Letters of the University of Zilina 2006, 8(1):39-42 | DOI: 10.26552/com.C.2006.1.39-42
Diamond and diamond-like carbon (DLC) layers are nowadays of increasing importance for electrical and mechanical applications. In our laboratory we grow diamond on different substrates (Si, WC-Co) using Hot Filament Chemical Vapor Deposition (HF CVD)method improved by double biasing and DLC layers using pulsed arc system again on different substrates (Si, Ni, glass, Ti-6Al-4V, steel, WCCo). Growth parameters facilitate to control crystallinity of diamond layers from microcrystalline to nanocrystalline type. Mechanical, electrical and optical parameters are possible to change using doping with hydrogen, nitrogen, or oxygen. The goal of this article...
Application of Communication Systems in Biomedical Engineering
Libor Hargas, Miroslav Hrianka, Pavol Spanik
Communications - Scientific Letters of the University of Zilina 2006, 8(1):43-47 | DOI: 10.26552/com.C.2006.1.43-47
Picture archiving and communication systems (PACS) in biomedical engineering consist of image and data acquisition, storage, and display subsystems integrated by various digital networks. The standard (DICOM 3) is applicable to a networked or an off-line media environment. It allows development and expansion of PACS system. This Standard has been developed with an emphasis on diagnostic medical imaging as practiced in radiology, cardiology and related disciplines. Also the compression methods suitable for image processing are presented in this article. The compression is often realized by reduction of irrelevance or redundancy. There are described...
Properties of Carbon Nanotubes and Their Use in Potential Applications
Anna Vojackova
Communications - Scientific Letters of the University of Zilina 2006, 8(1):48-50 | DOI: 10.26552/com.C.2006.1.48-50
Many laboratories in the world are doing research in the field of nanotechnology. Among lot of nanomaterials carbon nanotubes became very popular because of their unique properties which could be used in many applications. But first, lot of problems with their preparation need to be solved.
The Trans-European Transport Network (Ten-T): History, Progress and Financing
Boris Bottcher
Communications - Scientific Letters of the University of Zilina 2006, 8(1):51-54 | DOI: 10.26552/com.C.2006.1.51-54
Summing up, the author, M.E.S. (Master in European Studies) MA (International Relations) Dipl.-Ing. (Transport Sciences), presents the basis of his actual doctor thesis about the international and strategic dimensions of the enlargement of the Trans-European Network (TEN) to Russia, the caucasus and Turkey. The article deals with the creation and the development of the TEN-T program of the European Commission. After the description of the history of this program, the progress of the fourteen transport priority projects is shown from the report of the Christophersen group to the European Council in 1994. In addition, the guidelines and the financial...
The Introduction of the Austrian Toll System for Trucks - Effects on Companies
Marcus Einbock
Communications - Scientific Letters of the University of Zilina 2006, 8(1):55-59 | DOI: 10.26552/com.C.2006.1.55-59
This paper deals with effects of the Austrian road pricing system on enterprises. Trucks are charged per kilometre driving on Austrian motorways with the amount depending on the number of axles. Therefore, enterprises whose trucks use motorways are confronted with higher transport costs. These costs can be generally divided into direct and indirect ones. The main cost categories concerning indirect costs are costs for pre-financing, for bad debts losses and for toll-control. In this contribution these kinds of costs are assessed and the cost effects in different industries are evaluated. Further, empirical evidence based on a survey conducted in June...
Intermodality - Transportation Solution for Global Trade
Heda Hansenova, Ho Thi Thu Hoa
Communications - Scientific Letters of the University of Zilina 2006, 8(1):60-63 | DOI: 10.26552/com.C.2006.1.60-63
World trade has been growing at an average rate which is considerably greater than the growth rate of GDP (Gross Domestic Production). Policies aimed at the reduction of tariffs and quotas have led to an increase in the bilateral trade flows between countries. Increasing global trade also means that opportunities of transportation are growing. The efficient transportation solutions for global trade really offer demand for transport market by sea because of its satisfaction in long-distance routes as well as mass quantity of transported freight. Increasing business relations of two continents EU and Asia (especially ASEAN plus 3 named APT)1) are obviously...
A Note to Non-Traditional Systems of Public Transport
Anna Cerna, Jan Cerny
Communications - Scientific Letters of the University of Zilina 2006, 8(1):64-66 | DOI: 10.26552/com.C.2006.1.64-66
The paper deals with the following non-traditional (from the Czech point of view) solutions of public transport: * free competition of several providers, * use of heterogeneous rolling stock, * Dial-a-Ride systems and * integration with other systems.
Chosen Elements of Civilizational Selection Theory This is Why Unwilling Events Are Unavoidable
Jerzy M. Wolanin
Communications - Scientific Letters of the University of Zilina 2006, 8(1):67-69 | DOI: 10.26552/com.C.2006.1.67-69
Man has always lived in two spaces, natural environment and civilizational space. Civilizational space has been formed by man, is built up of all human activities, and has been created among others as human response to hazards. Variability of civilizational space causes the necessity of keeping up with changes. Things that were good yesterday today are of no value, which means they no longer protect from unwilling events. Description delay in relation to its constant change in civilizational space along with its complexity causes difference in interpretation. Occurrence of unwilling event is a sign that the accepted solution was bad and needs improvement....